Consider the set of ordered pairs $\{(-3, -6), (-2, -4), (-1, -2), (0, 0), (1, 2), (2, 4), (3, 6)\}$. To determine whether this relation is a function, observe if any $x$-value (first coordinate) is matched with multiple $y$-values (second coordinates). Each $x$-value in this relation—specifically $-3$, $-2$, $-1$, $0$, $1$, $2$, and $3$—is unique and corresponds to exactly one $y$-value, meaning the relation represents a true mathematical function. The function's domain is the explicit set of inputs: $\{-3, -2, -1, 0, 1, 2, 3\}$. The range is the explicit set of outputs: $\{-6, -4, -2, 0, 2, 4, 6\}$.